Active Tropics

The northern hemisphere tropics have taken another active turn. Starting in the Atlantic, after Danny dissipated in the northeast Caribbean, tropical storm Erika formed not too far behind in the central Atlantic. Erika then tracked mainly westward, following a similar track to Danny. Unlike Danny, however, Erika was a larger storm that struggled with wind shear its entire life. Erika tracked through the northeast Caribbean, crossed Haiti then Cuba where it degenerated into a tropical wave.

Erika’s heavy rains resulted in deadly flooding in parts of the northern Lesser Antilles islands. The remnants of Erika could cause hazardous flooding in parts of Florida and contribute to rainfall occurring across much of the southeastern United States over the next three days. As of 8am EST 30 Aug, the National Hurricane Center is giving the remnants of Erika a low chance of regeneration over the next 5 days as they track into the eastern Gulf of Mexico and then get drawn into an area of low pressure in the southeastern United States.

Tropical Storm Fred between the West Coast of Africa and the Cape Verde islands this morning.

In an unusual turn, Tropical Storm Fred has formed to the southeast of the Cape Verde Islands. Typically it takes several days over the open water for African easterly waves to organize into tropical cyclones and by then they are to the southwest or west of the Cape Verde Islands. In Fred’s case, the robust wave emerged into the Atlantic and almost immediately became a tropical cyclone. Fred is forecast to track northwestward, through the Cape Verde Islands and steadily strengthen along that path. Fred is expected to be over the Cape Verde Islands by Monday afternoon. This has warranted the issuance of Hurricane Warnings for those islands.

Terra MODIS satellite imagery from 29 Aug 2015 showing the three Pacific hurricanes. Hawaii can be seen between Kilo and Ignacio.

Meanwhile, three major hurricanes are simultaneously churning up the waters of the Tropical Pacific ocean. From west to east, Hurricane Kilo formed in the Central Pacific and very slowly organized into a tropical storm then hurricane. Kilo is about to cross into the Western Pacific area of responsibility where it will be renamed a Typhoon. After that, Kilo is forecast to take a turn to the northwest, but then turn back towards the west by Wednesday, some fluctuations in intensity are expected as vertical wind shear fluctuates along the path. Kilo is largely in the open Pacific ocean away from populated land.

Hurricane Ignacio formed in the Eastern Pacific and tracked westward into the Central Pacific. Ignacio is expected to pass north of the Hawaiian Islands starting on Tuesday. Elevated surf seems to be the primary threat there, but strong winds and gusty showers are also possible and tropical storm conditions are possible in those higher elevations – tropical storm watches are in effect for several of the Eastern Hawaiian islands. Ignacio is expected to weaken as it passes north of the islands as vertical wind shear increases.

Finally, Jimena is tracking westward through the Eastern Pacific. On this track, Jimena is forecast to cross into the Central Pacific by Wednesday. Jimena is forecast to remain far from any land for the next five days.

All three of these hurricanes were at category four strength as of the 11am EST update from the National Hurricane Center and Central Pacific Hurricane Center.